Interior micrometer.



N0.'890,59b. PATENTED JUNE 16, 1908. 4 A. L. ANDERSON. INTERIORMIGROMETBR. APPLICATION rm n MAB.23.1'908.

WITNESSES; v I INVENTOR.

mm mm w Jfi/fwi. I ATTIORNEY.

To all whom it may concern.-

AXEL L. ANDERSON. OF'H; \R'lF(.)RD, CONNECTICUT.

INTERIOR- MICROMETER.

Specification of Letters Patent.

Patented June 16, 1908.

Application filed March 23, 1908. Serial No. 422,586.

Be it known that I, AXEL L. ANDERSON, a citizen of the United States,and a resident of Hartford, in the county of Hartford and State ofConnecticut, have invented certain new and useful Improvements inInterior Micrometers, of which the following is a specification.

The object of the invention is to produce a device of the classspecified having features of novelty and advantage.

In the drawings-Figure 1 is a central vertical section Fig. 2 is abottom view.

adenotes the sleeve. In the form shown it has secured at its lower end aslotted cap I), the slots being substantially opposite one another.

c is a stem movable lengthwise in the sleeve and pivoted in the lowerend of this stem are oppositely curved jaws d d which extend out throughthe apertures, these jaws being offset at opposite sides as by therounded projections d d to bring the contact points on the central lineof the sleeve. The upper end of the stem is threaded preferably with afine pitch thread, and the interior of the sleeve is threaded with acoarse pitch thread, preferably one-half the pitch of the thread on thestem.-

A barrel -e fits closely the outside of the sleeve and has a tubularshank f which is threade'dexteriorly to fit the thread on the interiorof the sleeve and interiorly to fit the thread on the stem.

In practice I prefer to make the thread on the sleeve of 40 pitch andthe thread on the stem of 80 pitch sothat a one inchdownward movement ofthe barrel will cause a half inch downward movement of the stem.

Suitable divisions-are marked off lengthwise of the sleeve indicatinginches and fractions of an inch and the lower edge of the barrel isbeveled and divided off into divisions circumferentially in order thatthe exact size of the hole. which is being calipered may be read fromthis index.

The manner of use of a device of this kind is well known.

,stem movable lengthwise within the sleeve,

' stem jaws pivotally' secured to the lower end of said stern andpassing through said slots, and means for moving said stemlongitudinally within said sleeve:

2. An article of the character described comprising a sleeve slotted atits lower end, a stem movable lengthwise within the sleeve, jaws pivotedto the lower end of said stem and passing through said slots, a threadcut on the upper end of said stem, a thread cut on the interior of theupper end of said sleeve, abarrel fitting the outside of said stem, atubular shank in the barrel threaded exteriorly to fit the threads onthe interior of the sleeve and interiorly to fit the threads on thestem, substantially as described and for the purposes set forth.

3. In an article of the character described a tubular sleeve slotted atits lower end, a stem movable lengthwise therein, jaws pivoted to thelower end of said stem and passing through said slots, offsets at theends ofsaid jaws extending to opposite sides thereof, and means formoving said stern lengthwise Within said sleeve.

4. In an article of the character described a tubular sleeve, a slottedcap secured to the lower end thereof, a stem movable within the sleeve,jaws pivoted to the stem and passing through the slots in said cap, andmeans for moving the stem lengthwise of the sleeve, as and for thepurposes specified.

5. An article of the character described comprisinga sleeve havingopposite slots at its lower end, a stem movable lengthwise within thesleeve, abruptly diverging curved jaws movable through said slots andpivoted to saidstems, and means for moving said stemand jaws.

6. An article of the character described comprising a sleeve oppositelyslotted at its lower end, a stem movable lengthwise in said sleeve, apair of oppositely curved jaws pivoted to I the end of said stem andmovable throu h said slots, and means for movin said Iengthwise and theouter ends 0 said jaws'laterally with respect to said sleeve.

AXEL L. ANDERSON.

